Spotted stingaree

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Spotted stingaree
Urolophus gigas museum victoria.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Superorder: Batoidea
Order: Myliobatiformes
Family: Urolophidae
Genus: Urolophus
Species:
U. gigas
Binomial name
Urolophus gigas

The spotted stingaree (Urolophus gigas) is an uncommon species of stingray in the family Urolophidae, endemic to shallow waters along the coast of southern Australia. It favors rocky reefs and seagrass beds. This species can be readily identified by its nearly circular, dark-colored pectoral fin disc, adorned with a complex pattern of white or cream spots. Its eastern and western forms differ slightly in coloration and have been regarded as separate species. There is a skirt-shaped curtain of skin between its nostrils. Its tail is fairly thick and terminates in a short leaf-shaped caudal fin; a relatively large dorsal fin is present just in front of the stinging spine.

Contents

Rather reclusive, at least during the day, the spotted stingaree preys largely on crustaceans. It is aplacental viviparous: female bear litters of up to 13 pups and supply them with histotroph ("uterine milk") during gestation. Relatively inoffensive towards humans, the International Union for Conservation of Nature (IUCN) has listed this species under Least Concern, citing the overall low level of fishing activity across its range. Furthermore, it is sheltered from commercial fishing gear by the rough terrain of its favored habitats.

Taxonomy

The first known specimen of the spotted stingaree was collected off Port Noarlunga in South Australia, and described by Trevor Scott in a 1954 issue of the scientific journal Records of the South Australian Museum. The specific epithet gigas is Greek for "giant". [2] The eastern and western forms of this ray differ slightly in coloration; the western form, called Sinclair's stingaree, has been considered a distinct separate species by some authors. [3]

Distribution and habitat

Widely but patchily distributed along the southern coast of Australia, the spotted stingaree occurs from Albany, Western Australia to Lakes Entrance, Victoria, including Bass Strait and the northern Tasmanian coast. [1] It does not appear to be common, not does it aggregate any particular location. Bottom-dwelling in nature, this species inhabits the continental shelf from the intertidal zone to a depth of 50 m (160 ft). It is most commonly found in and around seagrass beds and rocky reefs, and has also been recorded from estuaries. [1] [4]

Description

The pectoral fin disc of the spotted stingaree is oval in shape and slightly longer than wide; it is more circular in juveniles. [4] The snout is fleshy and usually smoothly rounded, without a protruding tip. The eyes are tiny and followed by much larger comma-shaped spiracles, which have rounded posterior rims. There is a skirt-shaped curtain of skin with a finely fringed posterior margin between the nostrils. The floor of the small mouth bears 9–12 papillae (nipple-like structures); a further narrow patch of papillae is found on the lower jaw. [3] The teeth are small, with roughly oval bases. The five pairs of gill slits are short, and the pelvic fins are small and rounded. [5]

The tail measures 76–80% as long as the disc and is fairly thick, with an oval cross-section and no lateral skin folds. A serrated stinging spine is placed atop the tail and preceded by a prominent dorsal fin; the caudal fin is lance-like, short, and deep. The skin is completely smooth. The disc is dark brown to black above, becoming lighter towards the margins, and sometimes with irregularly scattered dark dots. There are 2–3 rows of small whitish spots that border the disc margin and may extend onto the tail, as well as much larger pale spots arranged in groups over the middle of the back. The areas before and behind the eyes, and a pair of patches at the back of the disc, are usually free of spots. The tail has a light stripe along the midline in juveniles, and light spots in some adults; the dorsal and caudal fins are dark brown to black with whitish edges. The underside is white or nearly so; most individuals have dusky blotches and wide bands bordering the lateral disc margins. In some rays the color pattern is faint. This species can grow up to 80 cm (31 in) long. [3] [6]

Biology and ecology

During the day, the spotted stingaree is often encountered buried in sand or hidden amongst seagrass or rocks. [3] [6] It feeds mainly on crustaceans. As in other stingrays, it is presumably aplacental viviparous with the developing embryos being nourished via maternal histotroph ("uterine milk"). Females can produce litters of up to 13 pups. Males and females reach sexual maturity at approximately 42 cm (17 in) and 46 cm (18 in) long respectively. [3]

Human interactions

Compared to some of its relatives like the sparsely-spotted stingaree (U. paucimaculatus), the spotted stingaree is less aggressive when disturbed by humans. [4] There is little to no fishing activity across most of this species' range, and its preference for rocky habitats mostly protect it from bottom trawls. The Southern and Eastern Scalefish and Shark Fishery (SESSF) take it as bycatch, but not in significant numbers. It may potentially be affected by habitat degradation or recreational fishing. Given that it is little threatened by human activity, the International Union for Conservation of Nature (IUCN) has assessed the spotted stingaree as of Least Concern. The range of this species encompasses a number of small Marine Protected Areas (MPAs), and it would potentially benefit from the implementation of the 2004 Australian National Plan of Action for the Conservation and Management of Sharks. [1]

Related Research Articles

<span class="mw-page-title-main">Urolophidae</span> Family of cartilaginous fishes

The Urolophidae are a family of rays in the order Myliobatiformes, commonly known as stingarees or round stingrays. This family formerly included the genera Urobatis and Urotrygon of the Americas, which are presently recognized as forming their own family Urotrygonidae. Stingarees are found in the Indo-Pacific region, with the greatest diversity off Australia. They are sluggish, bottom-dwelling fish that have been recorded from shallow waters close to shore to deep waters over the upper continental slope. Measuring between 15 and 80 cm long, these rays have oval to diamond-shaped pectoral fin discs and relatively short tails that terminate in leaf-shaped caudal fins, and may also have small dorsal fins and lateral skin folds. Most are smooth-skinned, and some have ornate dorsal color patterns.

<span class="mw-page-title-main">Western shovelnose stingaree</span> Species of cartilaginous fish

The western shovelnose stingaree is a common species of stingray in the family Urolophidae, inhabiting shallow sandy flats and seagrass beds off southwestern Australia from Perth to Gulf St Vincent. Growing to 37 cm (15 in) long, this small ray has a rounded pectoral fin disc and a blunt, broadly triangular snout. Its nostrils have enlarged lobes along the outer rims and a skirt-shaped curtain of skin between them with a strongly fringed posterior margin. Its tail ends in a lance-like caudal fin and lacks dorsal fins and lateral skin folds. This species is colored grayish to brownish above, sometimes with lighter and darker spots, and pale below, sometimes with darker marginal bands and blotches.

<span class="mw-page-title-main">Striped stingaree</span> Species of cartilaginous fish

The striped stingaree is a common but little-known species of stingray in the family Urolophidae, endemic to shallow, inshore waters off southwestern Australia. Reaching 61 cm (24 in) long, this species is characterized by an oval, grayish to brownish disc with darker mask-like markings around the eyes and paired blotches at the center of the disc that are extended posteriorly into horizontal lines. Its nostrils have enlarged lobes on the outer margins and a skirt-shaped curtain of skin with a deeply fringed trailing margin in between. Its tail terminates in a relatively large leaf-shaped caudal fin, and bears a small dorsal fin just before the stinging spine. The rounded, flexible disc of the striped stingaree enable it to maneuver through the rocks, reefs, and seagrass that comprise its favored habitats. The International Union for Conservation of Nature (IUCN) has listed this species under Least Concern; it is seldom caught by fisheries due to its habitat preferences.

The masked stingaree is a common species of stingray in the family Urolophidae, endemic to southwestern Australia. It prefers moderately deep areas of sand or seagrass some distance from shore, though it can be found in very shallow water or to a depth of 115 m (377 ft). The masked stingaree can be identified by the two large, dark blotches on the upper surface of its rounded pectoral fin disc, one of which encompasses its eyes like a mask. The outer rims of its nostrils are expanded into prominent lobes, while between the nostrils is a skirt-like curtain of skin with a deeply fringed trailing margin. Its tail bears a small dorsal fin just before the stinging spine, and end in a leaf-like caudal fin. This species grows up to 31 cm (12 in) across.

<span class="mw-page-title-main">Eastern shovelnose stingaree</span> Species of cartilaginous fish

The eastern shovelnose stingaree is a species of stingray in the family Urolophidae, endemic to coastal waters off southeastern Australia, excluding Tasmania. This species has a rounded pectoral fin disc wider than long, a fleshy snout forming an obtuse angle, and a relatively short tail terminating in a caudal fin. Its nostrils have prominent lobes on their outside rims and a skirt-shaped curtain of skin with a strongly fringed trailing margin between them. The dorsal coloration is mostly plain brownish, occasionally with a scattering of darker and/or lighter spots. One of the larger stingarees, it can grow to at least 80 cm (31 in) long.

<span class="mw-page-title-main">Common stingaree</span> Species of cartilaginous fish

The common stingaree is a species of stingray in the family Urolophidae. The most abundant ray in inshore waters off eastern Australia, it generally inhabits estuaries, sandy flats, and rocky reefs from the shore to a depth of 60 m (200 ft). This plain brownish to grayish species has a rounded pectoral fin disc with a broadly triangular snout. Its nostrils have enlarged lobes on their outer margins and a skirt-shaped curtain of skin with a fringed posterior margin between them. Its tail bears a small dorsal fin before the stinging spine, and terminates in a leaf-shaped caudal fin. This ray can grow to 52 cm (20 in) long.

The New Ireland stingaree or black-spotted stingaree, is a species of stingray in the family Urolophidae, known only from a single juvenile male 17.4 cm (6.9 in) long, collected in the Bismarck Archipelago. This species has an oval pectoral fin disc with tiny eyes and a rectangular curtain of skin between the nostrils. Its tail is fairly long and terminates in a leaf-shaped caudal fin, and lacks a dorsal fin. Uniquely among stingarees, it has rows of sharp spinules on the posterior portion of its back and the base of its tail. Its dorsal coloration is brown with dark spots. The International Union for Conservation of Nature (IUCN) has listed this ray as Data Deficient, pending more information.

<span class="mw-page-title-main">Sandyback stingaree</span> Species of cartilaginous fish

The sandyback stingaree or great stingaree is a little-known species of stingray in the family Urolophidae, endemic to southeastern Australia. It is generally found offshore around the edge of the continental shelf, at a depth of 65–265 m (213–869 ft). A relatively large species reaching 89 cm (35 in) long, the sandyback stingaree has a diamond-shaped pectoral fin disc wider than long, usually with a dorsal pattern of numerous fine lighter marks on a yellowish to brownish background. Its short tail terminates in a deep, leaf-shaped caudal fin, and bears a sizable dorsal fin just in front of the stinging spine.

The circular stingaree is an uncommon, little-known species of stingray in the family Urolophidae. Endemic to the coastal waters of southwestern Australia, it prefers a rocky and/or vegetated habitat. Reaching 60 cm (24 in) in length, this species is characterized by an oval pectoral fin disc bearing a striking dorsal pattern of lighter spots and rings, and a central circle of white-margined black spots, on a bluish gray background. Between its nostrils is a skirt-shaped curtain of skin, with the posterior corners drawn out into lobes. Its tail bears a rather large dorsal fin in front of the stinging spine, and ends in a deep, lance-like caudal fin. Negligibly affected by human activity, the circular stingaree has been listed under Least Concern by the International Union for Conservation of Nature (IUCN).

<span class="mw-page-title-main">Crossback stingaree</span> Species of cartilaginous fish

The crossback stingaree or banded stingaree is a species of stingray in the family Urolophidae. It is endemic to southeastern Australia, mainly off Victoria and Tasmania but also marginally to New South Wales and South Australia. This bottom-dwelling fish generally inhabits sand and reef habitats deeper than 100 m (330 ft) off Victoria, and muddy habitats in shallow bays and estuaries off Tasmania. Befitting its name, the crossback stingaree has a distinctive dark pattern on its back, consisting of a midline stripe that is crossed by three transverse bars. It has an oval pectoral fin disc with a blunt snout and a skirt-shaped curtain of skin between the nostrils. Its tail is short with no skin fold along the sides, and a deep, leaf-shaped caudal fin. The youngest rays may have a small dorsal fin in front of the stinging tail spine. This species reaches 50 cm (20 in) in length.

The Chesterfield Island stingaree or Deforge's stingaree is a little-known species of stingray in the family Urolophidae, endemic to the continental slope off the Chesterfield Islands. Reaching 34 cm (13 in) long, it has a rounded, diamond-shaped pectoral fin disc colored plain brown above and pale below, with a short head. There is a narrow, skirt-shaped curtain of skin between its nostrils. Its tail is relatively long and terminates in a leaf-shaped caudal fin; there are no dorsal fin or lateral skin folds. This species has been listed under Least Concern by the International Union for Conservation of Nature (IUCN), as there is little fishing activity within its range.

<span class="mw-page-title-main">Wide stingaree</span> Species of cartilaginous fish

The wide stingaree is a little-known species of stingray in the family Urolophidae, found off southwestern Australia. It typically occurs over sand in water 200–300 m (660–980 ft) deep around the edge of the continental shelf. This species has a broad diamond-shaped pectoral fin disc, a slightly pointed snout, and a tail with a leaf-like caudal fin, skin folds along either side, and no dorsal fins. Between its nostrils is a skirt-shaped curtain of skin. It is grayish green above, with faint bluish lines beside and behind the eyes. The maximum length on record is 52 cm (20 in).

The patchwork stingaree is a little-known species of stingray in the family Urolophidae, with a disjunct distribution off northwestern and northeastern Australia. It usually inhabits the outer continental shelf, at a depth of 60–320 m (200–1,050 ft). This species has a diamond-shaped pectoral fin disc much wider than long, and a short, flattened tail with a prominent dorsal fin and leaf-like caudal fin. There is a skirt-shaped curtain of skin between its nostrils. Its dorsal colour pattern resembles a mosaic of dark brown rings with light-coloured centers, separated by fine reticulated lines. The International Union for Conservation of Nature (IUCN) has listed the patchwork stingaree under Least Concern, as it is subject to minimal fishing pressure.

The lobed stingaree is a common species of stingray in the family Urolophidae, endemic to southern Western Australia in shallow, inshore sand and seagrass habitats. This species is plain sandy in colour above and has a broad, rounded pectoral fin disc. It is characterized by an enlarged, semicircular skin lobe of unknown function on the inner rim of each nostril. Its tail is slender, with lateral skin folds and a lance-like caudal fin but no dorsal fin. The maximum recorded width is 27 cm (11 in).

The mitotic stingaree or blotched stingaree, is a little-known species of stingray in the family Urolophidae, so named because it has light blue blotches on its back that resemble cells undergoing mitotic division. Though not uncommon, it is found only in a small area of the outer continental shelf off northwestern Australia, at around 200 m (660 ft) down. This species attains a length of 29 cm (11 in) long and has a diamond-shaped pectoral fin disc with broadly rounded corners and a skirt-shaped curtain of skin between the nostrils. Its tail has subtle skin folds running along either side, no dorsal fin, and a slender leaf-shaped caudal fin. The International Union for Conservation of Nature (IUCN) has listed the mitotic stingaree under Least Concern, as there is little fishing within its range.

<span class="mw-page-title-main">Sparsely spotted stingaree</span> Species of cartilaginous fish

The sparsely spotted stingaree, also known as the white-spotted stingaree or Dixon's stingaree, is a species of stingray in the family Urolophidae, common off the southern Australian coast. Preferring sandy flats and seagrass beds, this benthic ray can be found from close to shore to a depth of at least 150 m (490 ft), and tends to occur deeper in the northern portion of its range. Reaching a length of 57 cm (22 in), this species has a broad, diamond-shaped pectoral fin disc that is typically plain gray in color above with a V-shaped marking between the eyes. Individuals from southerly waters also generally exhibit a smattering of small, dark-edged white spots. This ray is further characterized by a distinctively bell-shaped curtain of skin between the nostrils. Its tail has a skin fold running along either side and a leaf-shaped caudal fin, but no dorsal fin.

The Coral Sea stingaree is a little-known species of stingray in the family Urolophidae, found at a depth of 171–310 m (561–1,017 ft) around the edge of the continental shelf off northern Queensland. Growing to a length of 48 cm (19 in), this species has a diamond-shaped pectoral fin disc with a protruding snout and a skirt-shaped flap of skin between the nostrils. Its tail bears a low dorsal fin before the stinging spine and terminates in a short leaf-shaped caudal fin. Its upper surface is grayish or brownish, sometimes with tiny dark spots. The Coral Sea stingaree may represent two closely similar species, one large and one small. There is very little fishing activity within its range, and thus it has been listed under Least Concern by the International Union for Conservation of Nature (IUCN).

<span class="mw-page-title-main">Kapala stingaree</span> Species of cartilaginous fish

The Kapala stingaree is a species of stingray in the family Urolophidae, endemic to inshore waters off southeastern Queensland and New South Wales. It is commonly found on and around rocky reefs at a depth of 10–130 m (33–427 ft). Reaching 51 cm (20 in) in length, the Kapala stingaree has a rounded, diamond-shaped pectoral fin disc and a slender tail, which ends in a leaf-shaped caudal fin and bears lateral skin folds and a small dorsal fin in front of the stinging spine. It has a distinctive bell-shaped curtain of skin between its nostrils. This species is greenish above, with a highly variable pattern of dark markings usually found outside and between the eyes, and over the back and tail.

<span class="mw-page-title-main">Greenback stingaree</span> Species of cartilaginous fish

The greenback stingaree is a little-known species of stingray in the family Urolophidae, endemic to the outer continental shelf and upper continental slope off southeastern Australia. Growing to a length of 51 cm (20 in), this species has a diamond-shaped pectoral fin disc wider than long and uniformly light green in color above. Between its nostrils is a skirt-shaped curtain of skin. Its tail bears skin folds on either side and a deep, lanceolate caudal fin, but lacks a dorsal fin.

The brown stingaree is a little-known species of stingray in the family Urolophidae, found at a depth of 60–220 m (200–720 ft) on the outer continental shelf off northern Western Australia. This species has a rhomboid pectoral fin disc colored light yellow or brown, sometimes with three faint, darker, transverse bars. Its nostrils have a skirt-shaped curtain of skin between them. Its tail ends in a leaf-shaped caudal fin and either lacks or has poorly developed lateral skin folds and a dorsal fin. The maximum known length is 36 cm (14 in). The International Union for Conservation of Nature (IUCN) has listed the brown stingaree under Least Concern, as there is negligible fishing pressure across most of its range.

References

  1. 1 2 3 4 Kyne, P.M.; Last, P.R.; Marshall, L.J. (2019). "Urolophus gigas". IUCN Red List of Threatened Species . 2019: e.T60094A68649513. doi: 10.2305/IUCN.UK.2019-1.RLTS.T60094A68649513.en . Retrieved 16 November 2021.
  2. ↑ Scott, T.D. (May 28, 1954). "Four new fishes from South Australia". Records of the South Australian Museum. 11 (2): 105–112.
  3. 1 2 3 4 5 Last, P.R. & J.D. Stevens (2009). Sharks and Rays of Australia (second ed.). Harvard University Press. p. 415–416. ISBN   978-0-674-03411-2.
  4. 1 2 3 Michael, S.W. (1993). Reef Sharks & Rays of the World. Sea Challengers. p. 91. ISBN   0-930118-18-9.
  5. ↑ Last, P.R. & L.J.V. Compagno (1999). "Myliobatiformes: Urolophidae". In Carpenter, K.E. & V.H. Niem (eds.). FAO identification guide for fishery purposes: The living marine resources of the Western Central Pacific. Food and Agricultural Organization of the United Nations. pp. 1469–1476. ISBN   92-5-104302-7.
  6. 1 2 Murch, A. Spotted stingaree. Elasmodiver.com. Retrieved on September 7, 2010.
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